Cranial nerve paralysis or paralysis caused by sensorimotor system diseases takes a fundamental means of human life and significantly reduces convenience of daily life. Such physically handicapped persons are increasing year by year. Recently, studies have been made on various technologies for assisting the physically handicapped persons in their physical exercise such as walking.
The assistance of the physical exercise includes an assistance of actual exercise, and an assistance used in training for facilitating exercise (refer to Patent Literature 1, for example). Examples include (1) a method using an external mechanical force, (2) a method using invasive electrical stimulation, and (3) a noninvasive electrical stimulation method, and the method using the external mechanical force is currently in the mainstream.
Although the method using the electrical stimulation is also useful, the method is not much used because of problems such as: (i) the stimulation cannot exert its effect for a long time because a user gets used to the stimulation, (ii) the stimulation may cause pain, (iii) the stimulation cannot exert its effect for a long time due to muscle fatigue because of reverse recruitment which is caused by the stimulation directly applied to the muscle from the outside, and (iv) the stimulation is prone to cause convulsions.